This invention relates to food processing, but more specifically to a method and an apparatus that chills large quantities of pre-cooked food items for storage and/or subsequent consumption.
Challenges in large-scale food production include identifying cooking techniques, preservation, spoilage, taste, quality control, pasteurization, storage, shipment, as well as the control and/or elimination of bacteria, viruses, and/or other microbiological agents. In order to quickly and conveniently serve large quantities of hot meals to a multitude of persons, it is often desirous to pre-cook foodstuffs; chill, pasteurize, and preserve the foodstuffs; and then heat and serve before consumption. Quick-chilling techniques, as they are terms, help provide a xe2x80x9cjust cookxe2x80x9d taste when cooked food is rapidly chilled from cooking temperature down to about near freezing levels.
Cryovac Sealed Air Corporation is one company that manufactures quick-chilling equipment as well as a Cook-Chill System where kettle-cooked foods are cooled in the same kettle. In blast chilling, cooked food items are packaged in nylon or plastic bags, and then blasted with chilled water and ice while circulating or tumbling in a chamber. Quick-chilling helps with pasteurization and bacteria control since cooked food items only momentarily reside at a temperature for bacterial growth. Ideally, cooked food is brought from a cooking temperature of about 100xc2x0 C. or more down to near zero degrees Celsius, but not frozen, as quickly as reasonably possible to avoid bacterial growth, which begins to occur above 4-5xc2x0 Celsius. Below that temperature, bacteria growth is nearly or completely arrested. Bacteria growth becomes critical, and begins to grow within seconds, between 5xc2x0 C. and 70xc2x0 C., but most bacterial agents are destroyed above 70xc2x0 C. Thus, it is important to chill cooked foods as quickly as possible. In large scale or mass food production, quick chilling requires relatively high amounts of energy. Thus, most prior systems had limited chilling capacity.
It is also desirous to cook foodstuffs (i.e., meats, vegetables, fish, foul, etc.) under pressure in order to provide higher cooking temperatures that which reduces cooking time and the escape of nutrients, vitamins, proteins, color, texture, etc. It is also desirous to avoid preservative or other additives and to vacuum pack prepared foods. Many prior methods and apparatuses, however, do not adequately employ these techniques.
Pasteurization is also important. This involves controlling food temperature initially from about 37xc2x0 C. to 100xc2x0 C., and then back down to about 3xc2x0 C. Considering that one BTU of energy is required to change the temperature of one pound of water by one degree, one million BTUs are required to chill 10,000 pounds of cooked food items by 100 degrees, assuming the food items contain mostly liquid or water (e.g., soups, stews, etc.).
As apparent, difficulties can become insurmountable in an effort to prepare and serve meals for 10,000 to 100,000 thousand people, or more. Preparing meals on-site near the time of consumption for this amount of people demand substantial on-site kitchens, facilities, dietary technicians, chefs and experienced food handlers.
The present invention addresses many of these problems.
In accordance with one embodiment, the invention comprises a method of quick-chilling foodstuff in a centralized kitchen facility having compartmentalized regions. The method comprises providing a water-filled reservoir, circulating water in the chamber, submersing coolant tubes in the water-filled reservoir, submersing packaged pre-cooked foodstuff in the reservoir, maintaining the water temperature less than 5xc2x0 Celsius by evaporating a coolant in the submersed coolant tubes and compressing the coolant at a location to vent heat to the external atmosphere, and removing the foodstuff when the temperature thereof reaches 5xc2x0 Celsius or less.
In accordance with another embodiment, a quick-chilling apparatus for chilling large quantities of foodstuff in a centralized kitchen facility, the apparatus comprising an endless flow coolant tank filled with water, a circulatory pump to circulate water in the tank, a series of evaporator coils submersed in the water, and a controller that controls a compressor to maintain the water temperature less than 5xc2x0 Celsius, where the compressor is located external of the region that houses the tank.
The above and other features of the invention will become apparent upon review of the following description taken with the accompanying drawings. The invention, though, is pointed out by the appended claims.